This invention relates to sensors or switches which utilize the fact that gravity will maintain an unrestricted conductive contact element, such as a metal ball or a ball of liquid mercury or other electrically conductive liquid, in the lowermost position relative to its containment chamber to indicate attitudinal position of the switch or sensor relative to true vertical, and correspondingly the attitudinal position of any object attached thereto. More particularly, the invention relates to such a sensor which is able to monitor the attitudinal position of an object relative to true vertical over a three axis pathway, such that a single sensor can monitor the movement over the pathway even if the object and sensor are inverted or tilted in any plane, and regardless of whether the object is fixed in space or moved positionally. Even more particularly, the invention relates to such a sensor where the operational sensor means is adjustable relative to a housing adapted to be connected to an object, such that the three axis pathway may be adjusted to account for attachment of the housing to a different object.
There are many situations where it is necessary or desired to monitor or sense the attitudinal position of an object relative to true vertical. Switches or sensors which utilize the effect of gravity on a ball of liquid mercury or an electrically conductive metal ball or roller are well known, the switch being designed such that the unrestricted conductive member makes or loses contact with a pair of leads in an electrical circuit dependent on the attitude of the switch relative to true horizontal, such that either contact with the leads or loss of contact with the leads which occurs when the attitudinal position of the switch is altered relative to vertical results in a signal or other electrical action occurring. Such switches or sensors are commonly referred to as mercury or gravity switches. Such simple gravity switches work when the object or switch is tilted or rotated about a non-vertical line, such that the switch is activated or deactivated when a particular angle relative to vertical is exceeded and gravity causes movement of the conducting ball away from or against the contact leads. In order to track attitudinal positioning of an object along various curved pathways in the orthogonal X-Y-Z three axis world, where the switch is rotated, tilted and/or inverted, the known solution is to attempt to combine a number of such two dimensional switches, with the switches oriented in opposing directions. Any such solution, especially when the object is inverted, requires determination of sequential activation and deactivation scenarios, since certain of the switches will be non-functional or provide incorrect signals when the object passes through various positions relative to vertical.
Switches of this type suitable for use in this invention are disclosed in my earlier and commonly owned U.S. Pat. No. 6,281,456, issued Aug. 28, 2001, U.S. Pat. No. 6,448,517, issued Sep. 10, 2002, U.S. Pat. No. 6,452,121, issued Sep. 17, 2002, U.S. Pat. No. 6,455,790, issued Sep. 24, 2002, and U.S. Pat. No. 6,486,422, issued Nov. 26, 2002, the disclosure of all being incorporated herein by reference.
It is an object of this invention to provide a sensor device having a single gravity-type sensor switch which monitors the position and orientation of an object over a three dimensional pathway which extends dimensionally about all three orthogonal axes, where the object may be tilted, rotated or inverted, as well as translated through space rather than maintained at a fixed location, so as to provide a signal to indicate that the object is moving in the predetermined three dimensional pathway, whereby the switch is disposed within an external or secondary housing in a manner that allows the position of the switch to be altered relative to the housing, thereby allowing the angle or plane of the pathway to be adjusted when the housing is attached to different objects. It is a further object of this invention to provide such a switch where the pathway is rotatably or pivotally adjustable relative to the housing about an axis, such that the pathway may be altered relative to one or more directions to increase the adaptability of the switch to changing circumstances.